Pressure measuring instrument



Dec. 21; 1948 A. LATEQRNSER 2,456,713

PRESSURE MEASURING 'INSTRUMENT Filed May 14, 1946' 2 snets-sneu 1 INVENTOR 7 BY h ir; w 1 M Dec. 21, 1948. A. LATERNSER I 2,456,713

PRESSURE MEASURING INSTRUMENT Filed May 14, 1946 2 Sheets-Sheet 2 INVENTOR ATTORNEYS Patented Dec. 21, 1948 Albin LaternserJ-inrgen, iass ignor to Laridisfziz GyryA? G., a bo'dycorporateof Switzerland Annamaria-s14, 1946,,SeiriaI-N LeGaGQi. In Switzerland June 27', 1945 provision of a novel and'flimprovedf-rin'gibalance of simplified constructionihaving a wideiriange of sensitivity for small. effectiveipressure'fdiflferences. A further object of th'e inventiori is the provision of a 'ring' balance" roviding for: a wider :range' of pressure (inferences, and ior' 'particular accuracy at low ranges. Theinvention furtheitzprovides a ring balance having a range;of'vsensitivity le'q'ua'l to or exceeding ithat -ofl'a fio'at' quantityi 'eter', Without the inconveniences attendant upon the use'of such float quantity meters. The invention further provides an improved means for measurin relatively small pressurenifierences at extremely high static;pressures- D Other objects and advantages .e -ibeiinven i will be set forth inpart hereinafter and in part will be obvious herefromyor'may b'elearned by practice with the invention," the same being realized and attainedby means=-;of the ins'trnmentalities and combinations pointed out in the appended claims.

The" invention consists. inanenovel partsficon structions; arrangements, "combinations" and improvements herein shown. arid'described. 'l

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together with the description, serve to explain the principles of the invention.

Of the drawings:

Figure 1 is a diagrammatic view illustrating the principle of a ring balance;

Figure 2 is a diagrammatic view, partially in section showing one embodiment of the present invention;

Figure 3 is a perspective view of a portion of the elements shown in Figure 2; I

Figure 4 is a fragmentary perspective view showing a modified form of the invention; and

Figure 5 is a fragmentary elevation of an additional modification of the invention.

Ring balances are useful for measuring diiferences in the static pressure of a fluid, gas or vapor, and are advantageous by reason of the ease with which the range of measurement of the instrument can be varied. As shown in Figure 1 of the drawing a ring balance I comprises an annular chamber of uniform cross section having a partition 2 dividing the upper half of the annular chamber into two parts 4 and 5 which communicate with the ports or couplings 6 and 1. At

screams: (midis-405) 2 V approximately the center of the ringisflmounted a knife edge pivot 9 supported by the" strut; 9a, th'ej pivot resting inthe seat 8; Approximately the lower) half of the annular 'chamberisflfilld, with a liquid la which is{considerablyheavier than the liquid, gas or vapor whose pressurens to be measured, this liquid being'prererablyrrom volatile. Diametricallybpposite' the partition 2, is a rod Ila rigidly fastened to and extending downwardly from the tube on which rod is car'- ried'a counterweight II which can be fixed atj a variable distance from the pivot}; Atone' side of thecounterweight H, preferably at'about"4 5'ff therefrom, is a pointer l ll'a also rigidly fastened to the tubeand cooperating :with the scal in te; provide for the direct'freading' of"thefpressure difference between the ports" fifa'nd "lg As'the pressure at port 6 is incurred, theliquidJdis pushed downwardly in'the chamber 4 andrises'a correspondin amountin the chamber 5; the by causing: the ring I to rotate in'ja clockwise direction carrying'wit wi l? P int r; .9 1 wfa rdly orr'the scale l 0. Such "a ring balance-can effectively serve to extract the squaicf root of h pressure differential existing "between the portsli and I, and I A v ,1 range between l5%and %0fthe full range orthe instrumentr According t t pr se t.) invention; the in body'forming'part of therin'g ballanceis provided with a greatly enlarged portion in the horizontal plane of the pivot or knife edge, which enlargement preferably takes the form or a substantially horizontal loop communicating with the ring body of the balance thereby providing a relatively large mass of heavy liquid which is displaced by relatively small pressure differential, without sacrificing the extremely wide range of pressures at which the balance is sensitive.

Referring now in detail to Figures 2 and 3 of the drawing, there is shown the present preferred and illustrative embodiment of the invention in which the ring body I is formed of a tube of uniform cross section terminating at its upper ends in the ports or open ends 6 and l at which the pressure connections are made. The lower half of the tube is formed as a semicircle, and is connected with the upper half of the tube by means of the horizontal loops l2 and I3, the entire tube being preferably formed as a single piece of bent tubing providing a continuous passageway of uniform cross sectional area from the upper open end 6 to the upper end 1. The lower half of the tube, and the lower half of each of the loops l2 and I3 is filled with the sealing its accuracy is usually'1limitedjtojthe liquid In of relatively heavy specific gravity, thereby forming a separating or sealing mass between the pressure chambers 3 and 5, as the sealing liquid in the lower half of the tube flows out into the horizontal loops and thus extends over a wider horizontal area than in the annular portion of the ring. Thereby thesmall diiference in pressure or small difference in the rotational position of the ring causes a greater displacement of the sealing fluid to one side or the other than plain annular ring of Figure wouldoccur with the 1. This greater displacement of sealing fluid due to the horizontal loops gives a greater trimming moment especially for relatively small quantities,

The range of the instrument is determined by the relation of the diameter of the ring body I to the cross-section of the loops i2 and i3. Prefa erably the measuring range is made to start at about 3 to 5% of the full scale reading 'of the balance by the relative adjustment of the diameter to the cross-section. I The form shown in Figures" 2 and 3 offers very definite advantages. by reason of its simplicity andinexpensiveness, the form. is. exceedingly compact, and due to the fact that it can be formed from a single piece of tubing Without wells, it is extremelyv reliable in operation.

4 Figure 4. of the drawingshows a modified form of the invention in which the ring i is perforated on opposite sides, the vertical distance between the apertures l4 beingabout half the diameter of the tube, and the loops, for instance i2, have their 'ends l2a shaped to fit the tube i and are welded or soldered thereto. The rings l2 and 53, as in Figure 2, extend inwardly from the ring 1! directly towards the knife edge 9.

Figure 5 of the drawing shows a further modifled form of the invention in which a sleeve 65 overlies'and is soldered to the ringv i and together with the ring I is apertured to receive and com municate with the horizontalhelical loop 42 (or l3). This form of the invention is advantageous in spite of its more complex construction inasmuch as the cross sectional area of the ring body and the junctions with the loops i2 andlt may be made equal without sacrificing the strength for by varying the pitch of the helical loops !2 4. and I3, the greater the pitch the less being the sensitivity.

Where the ring balance is used for the measurement Of difierential liquid pressures, the sealing fluid, of course, is immiscible with liquid whose pressure is being measured.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims and without departing from the principles of the invention and without sacrificing its chief advanta sv What is claimedis:

l. A rin balance for measurement of small pressure difierences having a hollow annulus the ends'of 'which are uppermost and connectible to the pressures to be measured, said hollow annulus 5. A ring balance asclaimed in claim 1 in,

which the hollow annulus and horizontal loops are of uniform interior cross section including the junctions of the loops and tube.

v ALBIN LATERNSER.

, REFERENCES orrnn The following references are of record in the file of this patent;

onrrnn srATEs PATENTS Number Name Date 1,504,045 'I-Iorton Aug 5,1924

FOREIGN PATENTS V Number x Country Date 157,986 Germany Jan. 27, 1905 537,550 Germany Nov. l, 1931 

